In the Linux kernel, the following vulnerability has been resolved:
Revert "ALSA: firewire-lib: operate for period elapse event in process context"
Commit 7ba5ca32fe6e ("ALSA: firewire-lib: operate for period elapse event
in process context") removed the process context workqueue from
amdtp_domain_stream_pcm_pointer() and update_pcm_pointers() to remove
its overhead.
With RME Fireface 800, this lead to a regression since
Kernels 5.14.0, causing an AB/BA deadlock competition for the
substream lock with eventual system freeze under ALSA operation:
thread 0:
* (lock A) acquire substream lock by
snd_pcm_stream_lock_irq() in
snd_pcm_status64()
* (lock B) wait for tasklet to finish by calling
tasklet_unlock_spin_wait() in
tasklet_disable_in_atomic() in
ohci_flush_iso_completions() of ohci.c
thread 1:
* (lock B) enter tasklet
* (lock A) attempt to acquire substream lock,
waiting for it to be released:
snd_pcm_stream_lock_irqsave() in
snd_pcm_period_elapsed() in
update_pcm_pointers() in
process_ctx_payloads() in
process_rx_packets() of amdtp-stream.c
? tasklet_unlock_spin_wait
ohci_flush_iso_completions firewire_ohci
amdtp_domain_stream_pcm_pointer snd_firewire_lib
snd_pcm_update_hw_ptr0 snd_pcm
snd_pcm_status64 snd_pcm
? native_queued_spin_lock_slowpath
_raw_spin_lock_irqsave
snd_pcm_period_elapsed snd_pcm
process_rx_packets snd_firewire_lib
irq_target_callback snd_firewire_lib
handle_it_packet firewire_ohci
context_tasklet firewire_ohci
Restore the process context work queue to prevent deadlock
AB/BA deadlock competition for ALSA substream lock of
snd_pcm_stream_lock_irq() in snd_pcm_status64()
and snd_pcm_stream_lock_irqsave() in snd_pcm_period_elapsed().
revert commit 7ba5ca32fe6e ("ALSA: firewire-lib: operate for period
elapse event in process context")
Replace inline description to prevent future deadlock.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.5): severity, escalated by confirmed exploitation. This CVE's 5.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it